whats the difference between a == and an === in javascript code example

Example 1: difference between == and === in javascript

0 == false   // true
0 === false  // false, because they are of a different type
1 == "1"     // true, automatic type conversion for value only
1 === "1"    // false, because they are of a different type
null == undefined // true
null === undefined // false
'0' == false // true
'0' === false // false

Example 2: === in js

<!DOCTYPE html>
<html>
<body>

<p id="demo"></p>

<script>

  var x = abc;
  document.getElementById("demo").innerHTML = (x === "ABC");

</script>

</body>
</html>